docs: def _check_scalar_vertical_extents(self, ds, z_variable):
          '''
          Check the scalar value of Z compared to the vertical extents which
          should also be equivalent
  
          :param netCDF4.Dataset ds: An open netCDF dataset
          :param str z_variable: Name of the variable representing the Z-Axis
          '''
          vert_min = ds.geospatial_vertical_min
          vert_max = ds.geospatial_vertical_max
          msgs = []
          total = 2
  
          zvalue = ds.variables[z_variable][:].item()
          if not np.isclose(vert_min, vert_max):
              msgs.append("geospatial_vertical_min != geospatial_vertical_max for scalar depth values, %s != %s" % (
                  vert_min,
                  vert_max
              ))
  
          if not np.isclose(vert_max, zvalue):
              msgs.append("geospatial_vertical_max != %s values, %s != %s" % (
                  z_variable,
                  vert_max,
                  zvalue
              ))
  
          return Result(BaseCheck.MEDIUM,
                        (total - len(msgs), total),
                        'geospatial_vertical_extents_match',
                        msgs)